In 1951, Dowker proved that a space $X$ is countably paracompact and normal if and only
if $X \times {\bf I}$ is normal. A normal space $X$ is called a Dowker space if $X \times
{\bf I}$ is not normal. The main thrust of this article is to extend this work with
regards $\alpha$-normality and $\beta$-normality. Characterizations are given for when the
product of a space $X$ and $(\omega + 1)$ is $\alpha$-normal or $\beta$-normal. A new
definition, $\alpha$-countably paracompact, illustrates what can be said if the
product of $X$ with a compact metric space is $\beta$-normal. Several examples demonstrate
that the product of a Dowker space and a compact metric space may or may not be
$\alpha$-normal or $\beta$-normal. A collectionwise Hausdorff. Moore space constructed by
M. Wage is shown to be $\alpha$-normal but not $\beta$-nornal.
Publié le : 2010-08-15
Classification:
$\alpha$-normal,
$\beta$-normal,
products,
Dowker,
Moore spaces,
$\alpha$-countably paracompact,
54D15
@article{1283967404,
author = {Ludwig, Lewis D. and Nyikos, Peter and Porter, John E.},
title = {Dowker spaces revisited},
journal = {Tsukuba J. Math.},
volume = {34},
number = {1},
year = {2010},
pages = { 1-11},
language = {en},
url = {http://dml.mathdoc.fr/item/1283967404}
}
Ludwig, Lewis D.; Nyikos, Peter; Porter, John E. Dowker spaces revisited. Tsukuba J. Math., Tome 34 (2010) no. 1, pp. 1-11. http://gdmltest.u-ga.fr/item/1283967404/